1. Field of the Invention
This invention relates to cushions for use as disposable bedding in pet carriers, crates, cages or other containers in which pets are transported or housed (for example, in hotels, homes, kennels and the like). The purpose of the cushion is to absorb pet urine, and to provide a comfortable, dry, thermal insulating surface for the pet to rest on. The invention was developed principally with cats in mind, but is equally well adapted for use in transporting dogs and other animals, both pets and others, in cages.
2. Description of the Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98.
There are a wide variety of commercially available carriers and cages for use in transporting animals. One example is the Pet Taxi, sold by Petmate of Arlington, Tex. Typically, these carriers are designed to be light, durable, easy to carry and easy to clean. For this reason, they typically have bottoms that are hard, provide little or no insulation, and are generally uncomfortable for an animal to sit on. This is a particular problem when the carriers are used for air transport of the animals, because they may be placed on very cold surfaces for very long periods. Most such carriers also do not make any provision for animal urine, though this is a frequent problem, either because the animal urinates due to the stress of being transported, or because it is confined in the carrier for a very long period.
A common method for dealing with these problems has been to simply place an old towel in the bottom of the cage. This provided for some cushioning and insulation, as well as some absorption of urine, if necessary. One problem with using a towel is that because it is not rigid the towel tends to become bunched at the end or side of the cage rather than remaining evenly spread across its bottom. A related problem is that a towel tends to slide under the animal, preventing the animal from getting or keeping its footing. This has the potential to cause the animal discomfort or injury. If a towel becomes urine soaked, it is uncomfortable and irritating for the animal to sit on, and unless promptly cleaned causes unpleasant odors and a potential sanitary problem. Finally, once the animal is removed from the carrier, this arrangement usually requires both the carrier and the towel to be cleaned—an unpleasant and time consuming chore.
There have been some attempts to improve upon the towel, none of which have been satisfactory. One class of products consists of a block of open cell foam or sponge, typically approximately 1.27 cm to 5.08 cm (0.5 inches to 2.0 inches) thick, typically sized to fit into the bottom of a carrier and typically sold with a covering. Typically the top covering is water-permeable. The most important disadvantage of these products is that the open cell foam only absorbs urine so long as the animal is not sitting or standing on it. When pressure is applied, the liquid is expressed out of the sponge. Since in this situation the animal has nowhere to stand or sit except on the cushion, the product simply does not work. Another disadvantage is that the cushion must be sized to fit the carrier within reasonable tolerances—since carriers come in a wide variety of shapes and sizes, a wide variety of cushion sizes and shapes would be required to cover the market. Another disadvantage is that between each use the foam or sponge must be cleaned and/or disinfected—which is difficult at best.
A variation on the foam/sponge approach is the PoochPad Ultra-Dry Transport System for Crates and Kennels, described at www.poochpad.com. This product substitutes a multi-layer cloth pad for the open cell sponge—in principle it is a variation on the towel. Like the sponge-based products, it does not keep the animal dry, if it is urinated upon, because it retains little fluid if the animal stands or sits on it (as it must in a carrier). It is also messy to clean.
U.S. Pat. No. 5,517,772, to Kamreth et al for Pet Carrier Absorbent Pad is yet another attempt to solve this problem. Kamreth's patent involves a layer of “driweave” material, described as “specially designed layers that provide a one way barrier to moisture,” placed over a layer of absorbent material, “such as felt, saw dust, or other desiccating material.” The biggest problem with the Kamreth invention is that it does not work, at least not with presently available fabric technology, because it depends on using a one way barrier to moisture, and no such barrier is presently available. Kamreth refers to this one-way barrier as “driweave.” DRI-WEAVE is a trademark of Procter & Gamble Co, and refers to the “topsheet component of catamenial products, namely sanitary napkins and pantiliners.” This material is water permeable in both directions. Another problem with the Kamreth invention is that it consists of a flexible sheet, and is therefore liable to slide or bunch, just like an old fashioned towel. The Kamreth invention attempts to solve this problem by use of adhesive strips, which is messy and unreliable.
A similar problem in a slightly different field is addressed by U.S. Pat. No. 4,800,677, to Mack for Animal Waste Collection Pad. The Mack invention, which is not meant to be used in a cage or carrier, consists of a permeable layer over an absorbent layer, over an impermeable layer. The liquid part of the animal waste passes through the permeable layer, is absorbed in the absorbent layer, and is prevented from spilling or leaking further by the bottom impermeable layer. After the animal eliminates on the Mack pad, the pad is picked up and thrown away. The Mack invention does not contemplate that the animal will stand or sit on the pad after elimination. Therefore, while the Mack invention is practical in its intended application outside of carriers or cages, it is not suitable for use in carriers or cages.
There is a large body of invention in the field of disposable diapers and sanitary products. One example, now in the public domain, is U.S. Pat. No. 4,333,463 to Holtman for Absorbent Structure Containing Superabsorbent. The basic elements of this technology have been available for a considerable period, and have been applied to pet waste disposal sheets similar in concept to the Mack pad. Examples include U.S. Pat. No. 5,797,347 to Ochi for Absorbent Panel for Pet Animals, and U.S. Pat. No. 6,227,145 to Miyamoto & Ochi for Household Animal Waste Collection Sheet. Although the super-absorbent properties of these pads would make them better suited for use in carriers or cages than the Mack pad, they are not optimized for this application. For example, the Ochi and Miyamoto & Ochi sheets both have a bottom layer which is liquid impermeable. This feature, which protects to some degree the underlying surface, also prevents the sheet from absorbing waste which accidentally gets spilled on the underlying surface. Also, because the Ochi and Miyamoto & Ochi sheets are not meant for the animal to sit on for any extended period, they lack the cushioning and insulation of the present invention.